Our long-term objective is to show that CAM techniques can improve management of inflammatory bowel disease (ibd) which includes Ulcerative Colitis (UC) and Crohn's Disease (CD). Our immediate objective is to determine whether a specific dietary intervention or a fructooligosaccharide (FOS) supplement has anti-oxidant or prebiotic effects and whether it is beneficial in the treatment of CD. Supporting a strong link between diet and CD, several epidemiological studies and therapeutic observations in the complementary and alternative medicine (CAM) literature suggest that diet is key to development of CD and its treatment. We took advantage of these CAM recommendations and designed a diet encompassing recommendations common to these CAM systems with particular attention to increasing the intake of dietary foodstuffs that have antioxidant and prebiotic effects. Using this diet together with a FOS supplement, our preliminary studies showed that our diet intervention is acceptable and well-tolerated and results in improvement of 66% of patients, reducing symptoms and/or the degree of inflammation. This finding now needs to be validated by a study with a stronger design, and the mechanisms underlying the effects of dietary manipulation-such as potential effects on microflora- need to be elucidated. In another pilot study using amplicon length heterogeneity, we demonstrated that the intestinal microflora of patients with CD differ significantly from healthy individuals. Whether we can normalize the microflora of CD patients, however, remains to be determined. Accordingly, we designed a study to test the hypotheses that: (1) dietary manipulation with either diet or a FOS supplement is an effective CAM therapy that prevents CD relapse (leads to maintenance of remission) and (2) such dietary manipulation can normalize the microflora of CD patients and decrease mucosal oxidative damage. Aim 1. To determine in a pilot, open-label study, whether dietary manipulation with a specific dietary therapy (that encompasses recommendations of various CAM practices) or a FOS supplement prevents flare-up in patients with inactive CD. Aim 2. To determine a) whether the same dietary manipulation with a specific dietary therapy or FOS normalizes colonic microflora and prevents mucosal oxidative damage in CD; and b) whether the observed changes correlate with clinical maintenance of remission. Significance. This study could provide information to suggest diet as a safe therapy for IBD and lay the groundwork for more definitive, randomized, controlled trials.